The invention relates to a padlock. There are previously known padlocks with removable shackles. An example of this is shown, for instance, in U.S. patent application Ser. No. 240,193, filed 03-03-1981. In this known padlock, the replacement of the shackle is possible only when the lock casing is opened and the lock mechanism removed. The removement of the lock mechanism is a complicated procedure.